Add Wireguard KeyGen Util

tools/AS1024.Wireguard.Utils.Cli/Program.cs

@@ -0,0 +1,47 @@
+using AS1024.Wireguard.Utils;
+
+const string Help =
+    """
+    wgkey - WireGuard key utility
+
+    wgkey gen
+    wgkey pub    <private-base64>
+    wgkey decode <key-base64>
+    """;
+
+if (args.Length == 0 || args[0] is "-h" or "--help" or "help")
+{
+    Console.WriteLine(Help);
+    return 0;
+}
+
+try
+{
+    // TODO: stdin mode?
+    switch (args[0])
+    {
+        case "gen":
+        {
+            var priv = WireGuardKeyUtils.GeneratePrivateKey();
+            var pub  = WireGuardKeyUtils.GetPublicKey(priv);
+            Console.WriteLine($"private={Convert.ToBase64String(priv)}");
+            Console.WriteLine($"public={Convert.ToBase64String(pub)}");
+            return 0;
+        }
+        case "pub" when args.Length == 2:
+            Console.WriteLine(Convert.ToBase64String(
+                WireGuardKeyUtils.GetPublicKey(WireGuardKeyUtils.FromBase64(args[1]))));
+            return 0;
+        case "decode" when args.Length == 2:
+            Console.WriteLine(Convert.ToHexString(WireGuardKeyUtils.FromBase64(args[1])).ToLowerInvariant());
+            return 0;
+        default:
+            Console.Error.WriteLine(Help);
+            return 1;
+    }
+}
+catch (Exception e) when (e is ArgumentException or FormatException)
+{
+    Console.Error.WriteLine(e.Message);
+    return 1;
+}